Timing device for telegraph circuit



, y 7, 1948. B. s. SWEZEY 2,445,809

TIMING DEVICE FOR TELEGRAPH CIRCUIT Filed Dec. 31, 1945 INVENTOR B. 5.SWEZEV A 7'7'ORNEV Patented July 27, 1948 TIMING DEVICE FOR TELEGRAPHCIRCUIT Burdette S. Swezey, Flor to Bell Telephone Lab New York, N. Y.,a cor al Park, N. Y., assignor oratories, Incorporated, poration of NewYork Application December 31, 1943, Serial No. 516,453

2 Claims.

This invention relates to timing devices for telegraph circuits.

An object of the invention is to provide an integrating timing devicewhich sums or integrates and indicates the total elapsed time duringwhich a channel of telegraphic transmission is operated. In the case ofa channel of telegraphic transmission which has a normal or markingcondition and a spacing condition, the channel is not considered to bein operation when it remains marking for a substantial length of time orwhen it remains spacing for a substantial length of time. Thus, forexample, if a customer pays for a circuit upon the basis of length oftime used, he would have to subtract from the total time not only thetime in which the channel remains marking but also the time in which itremains spacing. Thus, for example, it might remain spacin during timeswhen the channel is electrically open, grounded or otherwiseinoperative. The arrangement of the invention may, of course, beemployed for other useful purposes than charging a. customer, forexample, it might be used for supervisory purposes in checking theextent of use of the channel of transmission of any kind of an impulsetransmission system or for other purposes. Thus in the case of severalchannels of communication connecting the same two points, informationmight be gained by making use of the invention as to the desirability ornecessity of furnishing additional channels or removing from servicethose which are furnished, especially if the information as to the totaluse of each channel were supplemented by other information indicatingwhat portion of the time each particular channel has been found to beoperable and available for use. This arrangement may also be used torecord the approximate number of characters transmitted knowing the timeof operation and the speed of transmission, when automatic transmissionis employed.

The invention may be further explained in connection with theaccompanyin drawing in which the sole figure is a diagrammaticindication of a circuit arrangement comprising an exemplary embodimentof the invention.

Let it be assumed that it is desired to integrate the time of operationof any telegraph channel I which is indicated as incoming and outgoingline conductors including a relay 2 which may be of the polarized,unpolarized or of any other suitable type depending on the type oftelegraph channel or path in which the relay is connected. In an openand closed telegraph 2 path the relay 2 could be an ordinary unpolarizedrelay or a polarized relay equipped with a second winding for biasingcurrent approximately has the value of the line current as shown in thefigure; in a telegraph path transmitting polar signals the relay 2 couldbe a polar relay; in a path in which marking or spacing conditions arerepresented by groups of alternating current Waves the relay could be analternatin current relay; furthermore, the relay could be controlled bythe output path of a discharge tube rela having an input circuit shuntedacross the line and of a potential operated type which would abstractbut a small amount of power from the telegraph channel. Specifically, itmay be assumed in the disclosed embodiment that the telegraph line is aloop traversed by current pulses representing marking conditions andlittle or no current representing space conditions and that the markingconditions cause the relay 2 to maintain its contact 3 closed and thatthe relay responds to spacing conditions by closing the contact 4 underthe control of a local biasing circuit 5 acting upon a winding 5a. Aslow release relay 6 is connected in circuit with a local battery whenthe contact 3 is closed and a slow release relay 1 is connected incircuit with the same or another local battery when the contact 4 isclosed. If telegraph transmission is taking place, the contacts 3 and 4will be closed alternately in fairly rapid succession, the degree ofrapidity depending largely upon the type of telegraph code used intransmission. If we assume that the startstop five-unit printer codetransmitted from an automatic sender working at about 360 codecombinations per minute is employed, the maximum time during whicheither the contacts 3 or 4 remain closed will be not over about /6 of asecond except in the case of break signals which are ordinarily nottransmitted by an automatic transmitter but may upon occasion betransmitted by a supplemental key, or in the case of a keyboardtransmitter, by means of a break key attached to the machine. If it beassumed that the contact 3 is closed in the idle marking condition ofthe circuit, then the relay 6 will be energized and when transmissionbegins each spacing impulse will close the contact 4 and cause the relay1 to be energized. If each of these relays is of a type which requiresmore than second to release their armatures from their front contacts, apath 'will be closed continuously during the transmission from analternating current supply source 9 through the front contact of relay 1and the front contact of relay 6 to a self-starting electric device 8which may be similar to a self-starting electric clock well known in theart and commonly sold under the trade-mark Telechron or any otherelectrically driven time integrating and indicating device operated by aself-starting motor. For signal'counting the device 8 'may have its facecalibrated in numbers of characters. Any time the circuit or channel Iremains in marking condition continuously for more than about second,relay 6 will be released and stop the operation of the device 8 and anytime the channel I remains in spacing condition or open or grounded ordiscontinuous for more than about second, the relay 1 will release itsarmature and the device 8 will stop operating. Pjauses in transmissionfor small fractions of a second may stop the operation of the device 8and individual line hits may cause the device 8 to operate for periodsof time .of the order of a :iraction of a second when no intelligencetransmission has occurred; moreover, break signals :may stop theoperation of the device 8 for a period of time equal to the duration ofthe break signal less about /2 second. Break signals are relativelyinfrequent on most telegraphic circuits but in any case the total effectof break signals and other similar non-transmission conditions upon thedevice 8 Will be too small to prevent the obtaining of a reasonablyaccurate record, particularly as the efi-ects produced by some of theseconditions will be of a kind to record :too much time upon the device 8,and the effiects produced by other conditions will be of a nature tocause too .little time to be recorded on the device ,8, in consequenceof which they will in part neutralize one another.

It is understood that the telegraph channel I may comprise or includeinaddition to the relay .2 one or more .or any number, within practicallimits, of transmitters or transmitting keys and receiving or repeatingrelays or-equivalent elements. Such devices are well known in the 4 artand, consequently, are well understood 'without illustration in thedrawing.

What is claimed is:

1. An arrangement for indicating the time during which a telegraphchannel of transmission is used for transmission by means of a codewhich in normal transmission changes from one condition to another inthe maximum of a given time which comprises two electric circuit closingcontacts, instrumentalities so associated with the channel oftransmission and said contacts that they close and maintain saidcontacts closed during normal use of the channel of transmission and atime integrating device associated with a source of operating potentialthrough said contacts in such manner that it operates when both contactsare closed to integrate and indicate elapsed integrated time and ceasesto operate When either of said contacts is open.

2. A'telegraph channel for carrying intelligence in the form oftelegraphically coded impulses, means in said channel responding tochanges of impulse condition, a time integrating device associated withsaid means by means whereby the time integrating device indicates thesum of the time the telegraph channel is actually transmitting normaltelegraphic impulses separately from the time the channel stands idlewhether in marking or spacing condition, said last named means includingslow acting means, and a synchronous self-starting motor driven clockcontrolled by said slow acting means.

BURDETTE S. SWEZEY.

REFERENCES CITED UNITED STATES PATENTS Name Date Gardner et al May 6,1941 Number

